code: def set_txtsize(self, size):
      txtfont[1] = size
      self.text["font"] = tuple(txtfont)
      self.output_lbl["text"] = "Font size %d" % size
  
imports: import sys
  import os
  from tkinter import *
  from idlelib.colorizer import ColorDelegator, color_config
  from idlelib.percolator import Percolator
  from idlelib.textview import view_text
  from turtledemo import __doc__
  import turtle
label_desc: Use image node_id 5 for calling the DemoWindow obj's underlying member method code with example usage: obj.set_txtsize(size) without return types